Current memory technologies, including DRAM (dynamic random access memory), SRAM (static RAM) and NAND Flash, are quickly approaching their scalability limits. Accordingly, there is a strong need for new memory technologies that can meet the performance requirements of future memory applications. Candidates for the next-generation non-volatile storage applications, such as memristors, spin-transfer torque RAM (STT-RAM), phase-change RAM (PCRAM), conductive-bridging RAM (CBRAM), etc., are intended to be made to have a high device density. For instance, such devices may be formed in a crossbar array, wherein each bit at the intersection of a top crossbar wire with a bottom crossbar wire is a switching device. It is a challenge to fabricate such devices in a high density array with high yield and reliable device performance.